Obesity is defined as an “Excessive fat accumulation in the body to the extent that health and well-being are adversely affected”. It is a condition where a person’s Body Mass Index or BMI (calculated by dividing the height by weight) is more than 30. It is becoming a global epidemic not only in developed nations but also in developing nations.
The cause of severe obesity is poorly understood. There are probably many factors involved. In obese persons, the set point of stored energy is too high. This altered set point may result from a low metabolism with low energy expenditure, excessive caloric intake, or a combination of the above. Severe obesity is most likely a result of a combination of genetic, psycho-social, environmental, social and cultural influences that interact resulting in the complex disorder of both appetite regulation and energy metabolism.
Obesity can be treated both medically and surgically. Medical treatments for obesity are quite a time taking and difficult as the amount of weight loss is small and patients gain back most of the weight within no time. Surgeries designed to deal with weight loss in patients who are severely overweight and obese are called obesity and weight loss surgeries. However, controlled diet regimen and healthy lifestyle should be followed for best results of obesity and weight loss surgeries.
Bariatric surgery or weight loss surgery includes a variety of procedures performed on people who have morbid obesity. Weight loss is achieved by reducing the size of the stomach with a gastric band or through the removal of a portion of the stomach (sleeve gastrectomy or biliopancreatic diversion with duodenal switch) or by resecting and re-routing the small intestine to a small stomach pouch (gastric bypass surgery).
Types of Obesity Surgery
There are several types of restrictive, malabsorptive and combined procedures that can lead to sustained weight loss. Each one has its own benefits and risks. The top three procedures are:
Laparoscopic adjustable gastric banding (LAGB) or Laparascopic Gastric banding is one of the least invasive weight loss treatments available for obesity. It’s done with a few tiny abdominal cuts, instead of with one large cut. The surgeon puts instruments through the cuts. One of those instruments is a laparoscope, a tool with a tiny camera. Using this, a silastic band is placed around the stomach just below the junction of esophagus (food pipe). This forms a small pouch thus creating an hour-glass effect. The silicon ring passes around the stomach, thus giving a small outlet, that allows only as much food as the size of an eraser, to enter the distal stomach. The reservoir is placed under the skin in the midline just below the chest such that it can easily be felt while lying down. A needle can be injected through the skin into the reservoir and to add or remove fluid to adjust the size of the stomach outlet.
The hour glass configuration only constricts the upper stomach thus acting as a pure restrictive operation. Since the outlet is small, food stays in the pouch longer and one also feels satiated for a longer time. The small pouch ensures that the patient feels full after eating only small amounts of food. This causes weight loss. As its name suggests, this is an adjustable gastric band.
The sleeve gastrectomy originated as the restrictive part of the duodenal switch operation. In the last several years, it has also been used as a staging procedure prior to a gastric bypass or duodenal switch in very high-risk patients. It has also been used as a primary, stand-alone procedure.
Most sleeve gastrectomies performed today are performed laparoscopically. This involves making five or six small incisions in the abdomen and performing the procedure using a video camera (laparoscope) and long instruments that are placed through these small incisions.
Sleeve gastrectomy is a restrictive form of operation in which approximately 2/3rd of the left side of the stomach is removed laparoscopically using endoscopic staplers. The stomach thus takes the shape of a hockey stick or sleeve. It can be performed as either first stage of a two-stage procedure for super obese (BMI >60) where it can be followed with malabsorptive surgery or as a single stage procedure by itself.
The capacity of the stomach ranges between 60 – 100 cc. Unlike many other forms of bariatric surgery, the outlet valve and the nerves of the stomach remains intact while only the stomach size is drastically reduced. Though a non-reversible procedure, the part of the stomach that contains Ghrelin, the hormone for hunger is removed; it drastically reduces your appetite and hormones that controls diabetes.
The hour glass configuration only constricts the upper stomach thus acting as a pure restrictive operation. Since the outlet is small, food stays in the pouch longer and one also feels satiated for a longer time.
Gastric bypass, aka Roux-en-y gastric bypass surgery, involves creation of a small stomach pouch with the help of staples, which restricts the food intake. In addition, the initial segment of the small intestine is bypassed and a direct Y-shaped connection is made from the remaining part of the jejunum to the new stomach pouch for malabsorption.
Roux-en-Y gastric bypass (RYGB) reduces the size of the stomach to a small pouch – about the size of an egg. This therefore drastically reduces the amount of food intake. The surgeon then attaches this pouch directly to the small intestine, bypassing most of the rest of the stomach and the upper part of the small intestine. This reduces the amount of fat and calories absorbed from the foods taken and this causes, even more, weight loss.
Gastric bypass surgery can be done as an open surgery, with a large cut (incision) in the abdomen to reach your stomach. Or it can be done as a laparoscopic RYGB. Laparoscopic RYGB procedure means you don’t stay in the hospital as long and recover more quickly. You also may have less pain, smaller scars, and less risk of getting a hernia or infection.
This surgery, in effect is a combination of restriction & malabsorption. The small stomach created sends early signs of satiety and the bypass segment of the intestine leads to incomplete absorption of food. Hence there is a greater degree of weight loss than other procedures.
The most recent innovation in Bariatric surgery is the introduction of Robotic surgery. The surgeon operates the procedures through a master console and the robotic patient cart operates through tiny holes on the patient similar to laparoscopy with much ease and precision. Robotic surgery for obesity has definite advantages over conventional laparoscopic surgery due to its 3D vision and precise intuitive multi range instruments that add more safety to the patients. It also helps in better suturing skills and reduces post-operative pain and recovery time after surgery. It is indicated even for super obese patients more than 250 kgs which is more complicated and difficult to perform by laparoscopy.